Update notebook.py

notebook.py

@@ -28,6 +28,8 @@ def _(mo):
         One of the remarkable things about mathematical constants like $\pi$ is how frequently they arise in nature, in the most surprising of places.
 
         Inspired by 3Blue1Brown, this marimo notebook shows how the number of collisions incurred in a particular system involving two blocks converges to the digits in $\pi$.
+
+        **Tip!**: Use the menu in the top right to reveal the notebook's code.
         """
     )
     return